Lighter-colored tufts of hair along the back, red spots on top, and an orange stripe along each side distinguish its mature larvae from those of the rusty tussock moth. But recently, an online warning has been raising concerns about the moth's caterpillars. Mature larvae cease feeding and disperse to seek protected locations for spinning their silken, hair-covered cocoons. Forest Health Alert Douglas-fir tussock moth (Orgyia pseudotsugata): Outbreak status of a conifer defoliating caterpillar Importance. The Douglas-fir tussock moth, a native moth to the Sierra Nevadas, has fluctuating populations that, at times, burst with upsurges. The Douglas-fir tussock moth (DFTM) is a defoliating caterpillar that can severely damage Douglas-fir, true fir, and spruce trees in the western United States. The latest concern over the Douglas-Fir Tussock moth is that the caterpillar can cause allergic reactions in some people, but local experts say those reactions are rare.

The Douglas-fir tussock moth, O. pseudotsugata, feeds primarily on Douglas-fir and true firs. Some, however, are light bodied and look much like caterpillars of the whitemarked tussock moth, Orgyia leucostigma. Detailing the physical features, habits, territorial reach and other identifying qualities of the Fir Tussock Moth. The insect, during the caterpillar phase, defoliates Yosemite's white fir trees. The caterpillar, or larval, stage of these species often has a distinctive appearance of alternating bristles and haired projections. Most are dark bodied with orange spots as illustrated here. Tussock moth caterpillars (Orgyia species) occasionally occur in large numbers this time of year. Its brightly colored body is covered in fuzz, with tufts of hair on its back. The tussock moth caterpillar is quite the sight, if you’ve ever seen one hanging around a Douglas fir tree. Life cycle. Douglas fir tussock moths continue to spread across parts of Missoula. Many of its component species are referred to as "tussock moths" of one sort or another. While getting the supplies for the secret garden, I came across a tussock moth caterpillar. Tussock moths overwinter as eggs. The Lymantriinae (formerly called the Lymantriidae) are a subfamily of moths of the family Erebidae.The taxon was erected by George Hampson in 1893.. Mature Caterpillar: Fully-grown larvae are 1 to 1.5 inches long. This page details the Fir Tussock Moth including size, territorial reach and pictures.